synthtiger can't render text that contain '\u200c'

[mobassir94]

i was trying to generate bangla text recognition synthetic dataset using synthtiger like this : #25
i was able to generate many samples but sometimes it is failing by giving me this error :

Traceback (most recent call last):
  File "/home/apsisdev/.local/lib/python3.8/site-packages/synthtiger/gen.py", line 71, in _generate
    data = template.generate()
  File "/home/apsisdev/mobassir/bnsynthtiger/examples/synthtiger/template.py", line 109, in generate
    fg_image, label = self._generate_fg(fg_color, fg_style)
  File "/home/apsisdev/mobassir/bnsynthtiger/examples/synthtiger/template.py", line 182, in _generate_fg
    font = self.font.sample({"text": text, "vertical": self.vertical})
  File "/home/apsisdev/.local/lib/python3.8/site-packages/synthtiger/components/font/base_font.py", line 51, in sample
    path = meta.get("path", self._sample_font(text))
  File "/home/apsisdev/.local/lib/python3.8/site-packages/synthtiger/components/font/base_font.py", line 134, in _sample_font
    raise RuntimeError(
RuntimeError: There is no font that can render text 'র‌্যাডিসনে': /home/apsisdev/mobassir/bnsynthtiger/resources/font/bn

few more samples for what i got same error above :

1. 'শুনি—বাংলাদেশি'
2. 'কর‌্যা'
3. 'জাতীয়'
4. 'র‌্যাম্পের'
5. 'র‌্যাব-পুলিশ'
6. 'র‌্যাগিংয়ের'

text = 'র‌্যাব-পুলিশ'
[i for i in text]

we checked the failed samples with the code above,
seems like synthtiger is not able to render words that contain '\u200c'
not sure if there are any other failure cases though.

[monzzzz]

make sure that you extract the font using this:
python tools/extract_font_charset.py -w 4 fonts/